Teaching year 12 students from Harris Academy was awesome. Harris Academy are a consortium of 36 primary and state schools located all over South London. I had 26 of the lower sixth from the Peckham and Purley branches in the Reach Out Lab. I can’t help but feel these students are taking physics against the odds: they’re the students the experts worry about. Staff shortages led to them all being told they had to drop further maths- actually, to study maths at all they have to go to a nearby school. It’s common knowledge amongst the Harris students the ‘top’ achievers leave for sixth form at the prestigious Harris Academy Westminster Sixth Form, where of course you can study further maths, and those who are left feel rightfully despondent in a fancy building. Their physics teacher is a lovely and enthusiastic young man, but he isn’t a physicist… and he’s had to teach them chemistry too. So what happens to these guys? They’re hungry for science. They want to see experiments. They’re already much stronger than I’ve ever been- I was handed physics on a plate. They want to go to university to study maths. They want to study chemical engineering. They will not let legislation hold them back.
Over the day, we covered Fundamental Forces and Properties of Materials. You can download my slides here and here. We started with what we’d learnt from GCSE about atoms and nuclei, then what Rutherford discovered in 1913 then how we can predict nuclear fusion and fission based on atomic mass.
“If, as I have reason to believe, I have disintegrated the nucleus of the atom, this is of far greater significance than the war” Rutherford
It’s fun teaching radioactive decay- we learn very little more at university than we learn at school, and these guys knew just as much as me and all of the physics mentors. They didn’t really need teaching; they needed to be given confidence in their own abilities. We played with a protactinium radioactive source and tracked the half life, then mapped the shape of hidden objects by rolling marbles at an unknown shape. We also had a rather underwhelming cloud chamber, where on occasion you could observe a cosmic ray crossing a micro-mist of IPA. There was light in the darkness- the students spent the time asking the Imperial mentors questions about their university experiences. Next we considered the electromagnetic force and Einstein’s prediction of wave-particle duality. After a frantic search for a large enough piece of gold leaf- and a manic rush to the baking department in nearby Waitrose- we constructed our electroscope, which is basically a clean zinc plate connected to an empty box with a piece of (edible) gold leaf. The students were GREAT at charging the zinc plate- we’d been casually rubbing a polythene rod using our jumpers- their polyester school ties were fab. Finally, and randomly, but that is the A-level syllabus, we touched on the strong nuclear force and what holds protons and neutrons together. Particle physics is very ‘wordy’ when you’re at school, dropping words like quarks and strange and charm into your minds without much explanation. It doesn’t really change until you join a high-energy particle physics research group, and then only for those who actually go to CERN.
The afternoon was a more chilled affair- all about the material properties of sweets. After a very brief introduction to deformations, elasticity, stress, strain and Young’s Modulus, we characterised marshmallows, strawberry laces and crunchie bars. Fun fact! 2 cm of crunchie bar can withstand 69 N of force (7 kg weight), whilst one little malteaser celebration can take a massive 150 N. A strawberry lace can carry about 400 g until it breaks. During our evaluation session, we went through all the challenges and competitions going on at Imperial, along with our favourite physics revision guides and websites. I can’t believe how quickly the day went- it seems like we’d barely met and they were on the way home. On packing up the Reach Out Lab the latest box of earthworms (and preserved rats!) arrived for the life sciences workshops later in the week. Imperial are really exceptional at this activity: the ROL is better equipped than any research lab on campus, the teachers and mentors are more committed and enthusiastic than any lecturer and the behind-the-scenes team are totally non-vain- the day is totally about the students, and they can’t get enough.